First I'd check the billing cycle dates. Our vary from 26-34 days for seemingly no rhyme or reason. Also, sometimes ours are read both at that start of the month and the end. Sometimes the end is approximated, which can throw things off.

Outside of those two, no 3 degrees shouldn't be a 50% increase, but it sometimes matters how those 3 degrees happen. If you have cooler nights and slightly hotter days, that will be different than warmer nights with days a few degrees cooler for a high. Were you turning it down for bed at the same time both months? Were you turning it up later upon waking? Are you leaving the blower fan on now to circulate air? Any new large appliances? change in TV habits? Change in lighting habits?

Do you have a smart meter? Can you get the usage for a day you don't run the AC and compare it to one where you do use the AC?

Obviously, AC in the summer is probably your biggest draw. Is your hot water at the same setting? Is the same number of people using the same amount of electronics? You say it was a little warmer and you dropped the temp a little. Maybe it is a combination of that along with a bunch of other smaller things. If your "base" usage is low and the AC is a big portion of your bill, those relatively small differences in temp could make a big difference. By base I mean normal usage if you don't run heat/AC. Depending on your home, there are other factors beyond temperature that factor into the AC running. If it is sunny here, the AC will run much more than when it isn't even if the temp is the same.

My electric company always tells me I use way more than my neighbors but I don't put much weight into that. Some don't run (or have) the AC. Some live in apartments (I live in a very urban environment) or smaller places than I have.

Do you have a smart meter? Can you get the usage for a day you don't run the AC and compare it to one where you do use the AC?

Obviously, AC in the summer is probably your biggest draw. Is your hot water at the same setting? Is the same number of people using the same amount of electronics? You say it was a little warmer and you dropped the temp a little. Maybe it is a combination of that along with a bunch of other smaller things. If your "base" usage is low and the AC is a big portion of your bill, those relatively small differences in temp could make a big difference. By base I mean normal usage if you don't run heat/AC. Depending on your home, there are other factors beyond temperature that factor into the AC running. If it is sunny here, the AC will run much more than when it isn't even if the temp is the same.

My electric company always tells me I use way more than my neighbors but I don't put much weight into that. Some don't run (or have) the AC. Some live in apartments (I live in a very urban environment) or smaller places than I have.

Hot water setting, hmm. I do know that I turned it up after we moved in, but can't recall exact timing.

Not your issue, but a "friend of a friend" had an anecdote that their electric bill shot way up one month, like $200 -> $1200. It turned out the house had a driveway heater for melting snow that they didn't know about. They discovered it after the huge bill. I assume it looked like a normal switch to whoever turned it on by accident.

Do you have a smart meter? Can you get the usage for a day you don't run the AC and compare it to one where you do use the AC?

Obviously, AC in the summer is probably your biggest draw. Is your hot water at the same setting? Is the same number of people using the same amount of electronics? You say it was a little warmer and you dropped the temp a little. Maybe it is a combination of that along with a bunch of other smaller things. If your "base" usage is low and the AC is a big portion of your bill, those relatively small differences in temp could make a big difference. By base I mean normal usage if you don't run heat/AC. Depending on your home, there are other factors beyond temperature that factor into the AC running. If it is sunny here, the AC will run much more than when it isn't even if the temp is the same.

My electric company always tells me I use way more than my neighbors but I don't put much weight into that. Some don't run (or have) the AC. Some live in apartments (I live in a very urban environment) or smaller places than I have.

Hot water setting, hmm. I do know that I turned it up after we moved in, but can't recall exact timing.

Same # of people, 1 additional dog.

Definitely check the billing cycle to se if it is the number of days in 2017 vs 2018.
Also did you change any larger appliances or the way they are used? Like dryers, reefers, kitchen cooking, pool pumps, etc
After that consider this :
In 2017 your daytime setting was 78 with a daily average of 77 - a minus 1 degree demand.
In 2018 your daytime setting was 77 with a dialy average of 80 - a plus 3 degree demand.
Those were ffor maybe 10 hours or more a day when the temps and typically the highest.

Do you have a smart meter? Can you get the usage for a day you don't run the AC and compare it to one where you do use the AC?

Obviously, AC in the summer is probably your biggest draw. Is your hot water at the same setting? Is the same number of people using the same amount of electronics? You say it was a little warmer and you dropped the temp a little. Maybe it is a combination of that along with a bunch of other smaller things. If your "base" usage is low and the AC is a big portion of your bill, those relatively small differences in temp could make a big difference. By base I mean normal usage if you don't run heat/AC. Depending on your home, there are other factors beyond temperature that factor into the AC running. If it is sunny here, the AC will run much more than when it isn't even if the temp is the same.

My electric company always tells me I use way more than my neighbors but I don't put much weight into that. Some don't run (or have) the AC. Some live in apartments (I live in a very urban environment) or smaller places than I have.

Hot water setting, hmm. I do know that I turned it up after we moved in, but can't recall exact timing.

Same # of people, 1 additional dog.

Definitely check the billing cycle to se if it is the number of days in 2017 vs 2018.
Also did you change any larger appliances or the way they are used? Like dryers, reefers, kitchen cooking, pool pumps, etc
After that consider this :
In 2017 your daytime setting was 78 with a daily average of 77 - a minus 1 degree demand.
In 2018 your daytime setting was 77 with a dialy average of 80 - a plus 3 degree demand.
Those were ffor maybe 10 hours or more a day when the temps and typically the highest.

Yeah, that's why i also edited to note the avg daily use, which shot up 12 kWh or nearly 50%

Do you have a smart meter? Can you get the usage for a day you don't run the AC and compare it to one where you do use the AC?

Obviously, AC in the summer is probably your biggest draw. Is your hot water at the same setting? Is the same number of people using the same amount of electronics? You say it was a little warmer and you dropped the temp a little. Maybe it is a combination of that along with a bunch of other smaller things. If your "base" usage is low and the AC is a big portion of your bill, those relatively small differences in temp could make a big difference. By base I mean normal usage if you don't run heat/AC. Depending on your home, there are other factors beyond temperature that factor into the AC running. If it is sunny here, the AC will run much more than when it isn't even if the temp is the same.

My electric company always tells me I use way more than my neighbors but I don't put much weight into that. Some don't run (or have) the AC. Some live in apartments (I live in a very urban environment) or smaller places than I have.

Hot water setting, hmm. I do know that I turned it up after we moved in, but can't recall exact timing.

Same # of people, 1 additional dog.

Definitely check the billing cycle to se if it is the number of days in 2017 vs 2018.
Also did you change any larger appliances or the way they are used? Like dryers, reefers, kitchen cooking, pool pumps, etc
After that consider this :
In 2017 your daytime setting was 78 with a daily average of 77 - a minus 1 degree demand.
In 2018 your daytime setting was 77 with a dialy average of 80 - a plus 3 degree demand.
Those were ffor maybe 10 hours or more a day when the temps and typically the highest.

Yeah, that's why i also edited to note the avg daily use, which shot up 12 kWh or nearly 50%

"Yeah, that's why i also edited to note the avg daily use, which shot up 12 kWh or nearly 50%"
I don't know what size your AC unit(s) are but that is not an unusual figure since its 10 amps for 10 hours different.
So if your unit draws 20 amps that is 5 hours run time a day.

Jehova - I pulled out my last bill from my electric company. There is a section on it where they show me the detailed usage by month. It shows a graph showing kWh usage for the past thirteen months for comparisons. There is another section that shows more detail for this month, last month, and last year's equivalent month (August 2017). For each of these three months it shows kWh used, number of billing days, number of degree days, and total charges. The August 2018 bill shows we pay a monthly service charge of $16.90 plus an energy charge of $0.10527 per kWh, and a small TVA Fuel Cost Adjustment of $0.45.

For example my total bill for August 2018 was $123.96 and for August 2017 it was $104.75

My billing days for August 2018 was 30 and for August 2017 it was 31

My kWh usage for August 2018 was 1,017 and for August 2017 it was 887

My degree days for August 2018 was 458 and for August 2017 it was 403

I have been in this home since November 1995 and have kept a Excel spreadsheet of gas, water, and electric reflecting the total charges each month/year. I use the more current info to budget for utilities each year here in middle Tennessee. We keep the thermostat settings basically the same each year.

Thermostat during the day while at work was 78* last year, 77* this year.

Any thoughts? Is the outside avg temp change of only 3* enough to cause 50% increase in usage?

It was actually a 4 degree change since you made your house one degree cooler during the daytime this year. And yes a 4 degree change can make a significant difference though I wouldn't think 50%.

Like others said, check the cycle timing and also if any trueups have been done if you have an older style meter. On older meters that have to be read from the street versus sending out a signal directly to the utility company, they often will skip months between readings and just estimate based off history and then do a true up once in awhile.

Another thing I haven't seen mentioned but can play a huge part is the loss of a tree on a sun exposed side of the house or leaving open curtains on large windows that you previously kept closed. Large windows exposed to direct sunlight can create a tremendous amount of heat that your air-conditioning system has to offset. We lost a large tree that shaded a bay window on the west side of our house and it affected our air conditioning bill considerably until we put a curtain up.

Thermostat during the day while at work was 78* last year, 77* this year.

Any thoughts? Is the outside avg temp change of only 3* enough to cause 50% increase in usage?

It was actually a 4 degree change since you made your house one degree cooler during the daytime this year. And yes a 4 degree change can make a significant difference though I wouldn't think 50%.

Like others said, check the cycle timing and also if any trueups have been done if you have an older style meter. On older meters that have to be read from the street versus sending out a signal directly to the utility company, they often will skip months between readings and just estimate based off history and then do a true up once in awhile.

Another thing I haven't seen mentioned but can play a huge part is the loss of a tree on a sun exposed side of the house or leaving open curtains on large windows that you previously kept closed. Large windows exposed to direct sunlight can create a tremendous amount of heat that your air-conditioning system has to offset. We lost a large tree that shaded a bay window on the west side of our house and it affected our air conditioning bill considerably until we put a curtain up.

Hmm, we did have trees trimmed/cut down last Fall, but those are North facing and don't do much especially compared to the trees that block south facing sun. That said, I don't think those tree did much since there are trees behind those as well.

Does having a smart meter change a recording of usage?
I've noted an uptick in last 2 months usage (20%) on electric usage compared to last year same period and very little changed other than addition of the smart meter in June.

For example my total bill for August 2018 was $123.96 and for August 2017 it was $104.75

My billing days for August 2018 was 30 and for August 2017 it was 31

My kWh usage for August 2018 was 1,017 and for August 2017 it was 887

My degree days for August 2018 was 458 and for August 2017 it was 403

OK, degree days up ~14%.
And your thermostat is set a little lower.
KwH usage up 15%.

You're presumably using electricity for other purposes than just running the AC. Still, looking at KwH used versus degree days, and factoring in the lower thermostat setting, seems like it resolves most or perhaps all of the question.

EDIT - Never mind - I was indeed (as suggested below) confusing this poster for the OP.

Last edited by psteinx on Wed Sep 12, 2018 12:31 pm, edited 2 times in total.

After looking at billing cycle, curtains, shade issues and all other good advice already given here.

I would look at the cleanliness of the two AC coils one is outside and the other is inside. The interior one is referred to as a A coil due to its shape it is located inside in the duct work. My filters are kept clean and my electrostatic filter is washed regularly but still a fair amount of dust gets past and deposits accumulate on the interior of my A coil. It needs to be cleaned about every 24 months in my home. It is a difficult task for the novice but could incorporated into a biannual furnace service.

For giggles, at your peak usage time during the day, turn off all circuit breakers and verify the meter is at a dead stop. If not you have a problem! Then turn on each circuit and jot down what is actually on it and running. Take a look at the meter to get a sense off the draw. Turn off, go to the next circuit and do the same. Continue until all are completed. Surprisingly how much power is used for computers, home networks, security cams, cell phones, tablets along with TV's, stereos, cable boxes and other items that are "off" but still "ON" standby. Also, you might find a circuit going to the garage or placed outside is drawing power.

There are probably better ways of doing this but it worked in my small place. It was enlightening.

Any thoughts? Is the outside avg temp change of only 3* enough to cause 50% increase in usage?

This happened to us: I live thousands of miles from a deceased relative's unoccupied condo. Helpful neighbor turned on the heater at the thermostat but switched the blower from "Auto" to "On." The temp was set correctly but the blower motor consumed like $300/month in electricity for a small condo. I did not realize until I saw the electric bill (which comes to my address). As soon as I flipped that switch, we were back to baseline consumption. Expensive lesson.

1) Find your electric meter, figure out how to convert dial spins or whatever to KwHs used, then power your house down and slowly turn back on major systems. Be aware that this is a crude tool at best for certain major systems that only kick into high usage periodically (HVAC, refrigerator, electric water heater).

2) Use a Kill-a-Watt type device to chase down usage of smaller devices.

Thermostat during the day while at work was 78* last year, 77* this year.
Can't recall nigh-time setting as we like to keep it cool at bedtime, last year either 69 or 70* this year 69* for sure.

Those are the only variables I can think of. The filter is usually changed ahead of schedule due to having dogs in the house and same rating/brand filter.

Any thoughts? Is the outside avg temp change of only 3* enough to cause 50% increase in usage?

FWIW, our bill was $215 this time which I assume is still very decent compared to other homes, though our energy report doesn't show us among the most efficient compared to other months.

Also to note, July's usage from year to year, differed by 4 kWh/day avg

The first thing I would look at is increased AC use. Next, the fridge could be drawing more power--clean off the coils. Those are typically the biggest power users. If you have an electric heater or electric water heater, look at those also.

Thermostat during the day while at work was 78* last year, 77* this year.
Can't recall nigh-time setting as we like to keep it cool at bedtime, last year either 69 or 70* this year 69* for sure.

Those are the only variables I can think of. The filter is usually changed ahead of schedule due to having dogs in the house and same rating/brand filter.

Any thoughts? Is the outside avg temp change of only 3* enough to cause 50% increase in usage?

FWIW, our bill was $215 this time which I assume is still very decent compared to other homes, though our energy report doesn't show us among the most efficient compared to other months.

Also to note, July's usage from year to year, differed by 4 kWh/day avg

The first thing I would look at is increased AC use. Next, the fridge could be drawing more power--clean off the coils. Those are typically the biggest power users. If you have an electric heater or electric water heater, look at those also.

Hmm, our last house we had a gas water heater and never had it serviced in 6 yrs but that was on city water.

We are now on well water with low hardness but havent had the electric water heater serviced yet.

Last edited by jehovasfitness on Wed Sep 12, 2018 8:22 pm, edited 1 time in total.

Any thoughts? Is the outside avg temp change of only 3* enough to cause 50% increase in usage?

This happened to us: I live thousands of miles from a deceased relative's unoccupied condo. Helpful neighbor turned on the heater at the thermostat but switched the blower from "Auto" to "On." The temp was set correctly but the blower motor consumed like $300/month in electricity for a small condo. I did not realize until I saw the electric bill (which comes to my address). As soon as I flipped that switch, we were back to baseline consumption. Expensive lesson.

Hard to believe $300/ monthy for just a blower in a condo. We run our fan "on" all the time when it's AC season, and our TOTAL bill for a 2 story house 2100 sq ft is less than $300.

Any thoughts? Is the outside avg temp change of only 3* enough to cause 50% increase in usage?

This happened to us: I live thousands of miles from a deceased relative's unoccupied condo. Helpful neighbor turned on the heater at the thermostat but switched the blower from "Auto" to "On." The temp was set correctly but the blower motor consumed like $300/month in electricity for a small condo. I did not realize until I saw the electric bill (which comes to my address). As soon as I flipped that switch, we were back to baseline consumption. Expensive lesson.

Hard to believe $300/ monthy for just a blower in a condo. We run our fan "on" all the time when it's AC season, and our TOTAL bill for a 2 story house 2100 sq ft is less than $300.

What can I say? I'm a huge liar.

Actually, the bill went from << $100 to > $300 so maybe "only" $200 - $250 was from the blower. But, yes, it was the blower. Two months. Stopped when we switched the fan back to auto. It was almost the only electricity being used in the condo. The condo is a little bigger than your house, btw, but it was an ordinary furnace. You're probably spending a lot for yours but I'm sure you track that.

If you have a smart meter your elec. company should offer the hourly tracking of usage tool online. Altho it is time-consuming, and a chore, the only way to track this down is to closely monitor your usage that way.

FWIW - When our area went to the smart meters several years ago one of the arguments opponents used was that bills inexplicably went up, not the same, with smart meters. Last winter, I noticed an unusual spike in my kw in the middle of the day. The spike was quite noticeable, kw usage would jump from like half a kw or so to 3.4, 3.8, one time over 4 kw. That type of high kw reading for a 60-minute period in my house could only mean heat pump transitioning to the heat strip mode. Or running a load of clothes in dryer while using the oven also.
Since I kept good notes of everything I knew the heat pump had not come on, nor the compressor to the fridge. Was not doing laundry or using any hot water. After about 10 days of watching this mysterious jump in kw, I called the elec. company to file an inquiry/complaint.

They first denied that the smart meter would malfunction. Just not possible. When pressed, the rep admitted that in the few cases where it did malfunction, it was not spiking but the opposite, failing to record actual kw usage. I insisted that something was haywire, and since nothing in the household was using that much electricity at those hours, the problem had to be with the meter.

After more back and forth, the rep assured me he would look into the matter further and consult with the engineering dept.

Guess what. After that, the spiking every day in the middle of the day suddenly stopped. Just like that. There was only one conclusion I could draw from this experience.

So, a word to the wise. Keep a close eye on every hour the smart meter records your usage. You can't do this in real time, there is a 24-hour lag until the data is posted online. So you must keep good notes of what activity there was in the house, and at what times, the previous day.

(For the record, my elec. company is Delmarva Power, a subsidiary of PEPCO, which is now subsidiary of Exelon)

If you have a smart meter your elec. company should offer the hourly tracking of usage tool online. Altho it is time-consuming, and a chore, the only way to track this down is to closely monitor your usage that way.

FWIW - When our area went to the smart meters several years ago one of the arguments opponents used was that bills inexplicably went up, not the same, with smart meters. Last winter, I noticed an unusual spike in my kw in the middle of the day. The spike was quite noticeable, kw usage would jump from like half a kw or so to 3.4, 3.8, one time over 4 kw. That type of high kw reading for a 60-minute period in my house could only mean heat pump transitioning to the heat strip mode. Or running a load of clothes in dryer while using the oven also.
Since I kept good notes of everything I knew the heat pump had not come on, nor the compressor to the fridge. Was not doing laundry or using any hot water. After about 10 days of watching this mysterious jump in kw, I called the elec. company to file an inquiry/complaint.

They first denied that the smart meter would malfunction. Just not possible. When pressed, the rep admitted that in the few cases where it did malfunction, it was not spiking but the opposite, failing to record actual kw usage. I insisted that something was haywire, and since nothing in the household was using that much electricity at those hours, the problem had to be with the meter.

After more back and forth, the rep assured me he would look into the matter further and consult with the engineering dept.

Guess what. After that, the spiking every day in the middle of the day suddenly stopped. Just like that. There was only one conclusion I could draw from this experience.

So, a word to the wise. Keep a close eye on every hour the smart meter records your usage. You can't do this in real time, there is a 24-hour lag until the data is posted online. So you must keep good notes of what activity there was in the house, and at what times, the previous day.

(For the record, my elec. company is Delmarva Power, a subsidiary of PEPCO, which is now subsidiary of Exelon)

Very helpful!
I will track this and have a conversation with the utility. They already fessed up they "forgot" my promotion for agreeing to the smart meter in the first place as I didn't get any bill credit for the last 3 months, and will now honor that.

drawpoker wrote: (For the record, my elec. company is Delmarva Power, a subsidiary of PEPCO, which is now subsidiary of Exelon)

.......They already fessed up they "forgot" my promotion for agreeing to the smart meter in the first place as I didn't get any bill credit for the last 3 months, and will now honor that.
[/quote]

I have some history with Delmarva Power as a whistleblower, a troublemaker. That may have had something to do with why I got such quick action.

Four years ago, I had to sic the Office of Peoples Counsel on them over a sudden and unannounced change they made in applying credit balances to customer accounts. Since I knew they had not filed notice of this change with the PSC staff, and the company CSR refused to listen to me, I took is straight to the OPC in Baltimore. They agreed immediately it was not kosher and took up my case. In less than 10 days they notified me that Delmarva Power had acknowledged the "mistake" and had taken steps to reverse it back to what it should be.

But, know what? The company never admitted to the OPC or PSC this was a deliberate grab, they instead conveniently blamed the "mixup" on the switch to a new computer system. Also, due to public records law here, Delmarva knew the name and address of the customer who ratted on them.

I never believed that story (computer error) then, and still don't believe it now. Of course, I would never tell them that, I prefer to think that I am getting kid gloves treatment from them since they know me to be a troublemaker.

Another thing to look for: Before smart meters, a portion of your bill represented a small charge (hidden deep within some category) to recoup the cost of having meter readers go out every month. With the installation of the new meters, did that charge disappear from your bill? I was told confidentially by a company employee that it did not.

Given when the house was built, it should be relatively well insulated. Unfortunately air tightness can vary a lot and that has a big impact - at your levels of insulation probably a greater impact. A hole in the envelope can negate all the good work from the higher standards of insulation and windows, etc.

Thus, the change in average temperature should not have such a big impact on consumption - whereas for an older, less well insulated house, it would.

Given when the house was built, it should be relatively well insulated. Unfortunately air tightness can vary a lot and that has a big impact - at your levels of insulation probably a greater impact. A hole in the envelope can negate all the good work from the higher standards of insulation and windows, etc.

Thus, the change in average temperature should not have such a big impact on consumption - whereas for an older, less well insulated house, it would.

Yeah, house seems to hold temp very well and all windows are high efficiency ones or low-E whatever the correct term is

Another thing to look for: Before smart meters, a portion of your bill represented a small charge (hidden deep within some category) to recoup the cost of having meter readers go out every month. With the installation of the new meters, did that charge disappear from your bill? I was told confidentially by a company employee that it did not.

Fascinating, thanks drawpoker!
I will look over the line items and see what the differences are.
I will make sure to request this.

Seems like you need more data. Were you on vacation for a week or two in August 2017? How does July 2018 compare to August 2018 in kwh used per day? Did you put in a second refrigerator/freezer or other high electricity usage appliance after you moved in? Do you have a pool or spa?